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Merge pull request 'FixedTimeslotTask FreeRTOS improvements' (#117) from KSat/fsfw:mueller_FixedTimeslotTaskImprovements into master

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This commit is contained in:
Steffen Gaisser 2020-07-14 11:45:41 +02:00
commit 639e61cebf
2 changed files with 113 additions and 70 deletions
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86
osal/FreeRTOS/FixedTimeslotTask.cpp
View File

@ -1,6 +1,7 @@
#include <framework/serviceinterface/ServiceInterfaceStream.h>
#include "FixedTimeslotTask.h"
#include <framework/serviceinterface/ServiceInterfaceStream.h>
uint32_t FixedTimeslotTask::deadlineMissedCount = 0;
const size_t PeriodicTaskIF::MINIMUM_STACK_SIZE = configMINIMAL_STACK_SIZE;
@ -18,16 +19,19 @@ FixedTimeslotTask::~FixedTimeslotTask() {
void FixedTimeslotTask::taskEntryPoint(void* argument) {
//The argument is re-interpreted as FixedTimeslotTask. The Task object is global, so it is found from any place.
// The argument is re-interpreted as FixedTimeslotTask. The Task object is
// global, so it is found from any place.
FixedTimeslotTask *originalTask(reinterpret_cast<FixedTimeslotTask*>(argument));
// Task should not start until explicitly requested
// in FreeRTOS, tasks start as soon as they are created if the scheduler is running
// but not if the scheduler is not running.
// to be able to accommodate both cases we check a member which is set in #startTask()
// if it is not set and we get here, the scheduler was started before #startTask() was called and we need to suspend
// if it is set, the scheduler was not running before #startTask() was called and we can continue
/* Task should not start until explicitly requested,
* but in FreeRTOS, tasks start as soon as they are created if the scheduler
* is running but not if the scheduler is not running.
* To be able to accommodate both cases we check a member which is set in
* #startTask(). If it is not set and we get here, the scheduler was started
* before #startTask() was called and we need to suspend if it is set,
* the scheduler was not running before #startTask() was called and we
* can continue */
if (!originalTask->started) {
if (not originalTask->started) {
vTaskSuspend(NULL);
}
@ -58,11 +62,6 @@ ReturnValue_t FixedTimeslotTask::startTask() {
ReturnValue_t FixedTimeslotTask::addSlot(object_id_t componentId,
uint32_t slotTimeMs, int8_t executionStep) {
if (objectManager->get<ExecutableObjectIF>(componentId) != nullptr) {
if(slotTimeMs == 0) {
// FreeRTOS throws a sanity error for zero values, so we set
// the time to one millisecond.
slotTimeMs = 1;
}
pst.addSlot(componentId, slotTimeMs, executionStep, this);
return HasReturnvaluesIF::RETURN_OK;
}
@ -81,8 +80,9 @@ ReturnValue_t FixedTimeslotTask::checkSequence() const {
}
void FixedTimeslotTask::taskFunctionality() {
// A local iterator for the Polling Sequence Table is created to find the start time for the first entry.
auto slotListIter = pst.current;
// A local iterator for the Polling Sequence Table is created to find the
// start time for the first entry.
FixedSlotSequence::SlotListIter slotListIter = pst.current;
//The start time for the first entry is read.
uint32_t intervalMs = slotListIter->pollingTimeMs;
@ -90,29 +90,65 @@ void FixedTimeslotTask::taskFunctionality() {
TickType_t xLastWakeTime;
/* The xLastWakeTime variable needs to be initialized with the current tick
count. Note that this is the only time the variable is written to explicitly.
After this assignment, xLastWakeTime is updated automatically internally within
vTaskDelayUntil(). */
count. Note that this is the only time the variable is written to
explicitly. After this assignment, xLastWakeTime is updated automatically
internally within vTaskDelayUntil(). */
xLastWakeTime = xTaskGetTickCount();
// wait for first entry's start time
if(interval > 0) {
vTaskDelayUntil(&xLastWakeTime, interval);
}
/* Enter the loop that defines the task behavior. */
for (;;) {
//The component for this slot is executed and the next one is chosen.
this->pst.executeAndAdvance();
if (pst.slotFollowsImmediately()) {
//Do nothing
} else {
// we need to wait before executing the current slot
//this gives us the time to wait:
if (not pst.slotFollowsImmediately()) {
// Get the interval till execution of the next slot.
intervalMs = this->pst.getIntervalToPreviousSlotMs();
interval = pdMS_TO_TICKS(intervalMs);
checkMissedDeadline(xLastWakeTime, interval);
// Wait for the interval. This exits immediately if a deadline was
// missed while also updating the last wake time.
vTaskDelayUntil(&xLastWakeTime, interval);
//TODO deadline missed check
}
}
}
void FixedTimeslotTask::checkMissedDeadline(const TickType_t xLastWakeTime,
const TickType_t interval) {
/* Check whether deadline was missed while also taking overflows
* into account. Drawing this on paper with a timeline helps to understand
* it. */
TickType_t currentTickCount = xTaskGetTickCount();
TickType_t timeToWake = xLastWakeTime + interval;
// Tick count has overflown
if(currentTickCount < xLastWakeTime) {
// Time to wake has overflown as well. If the tick count
// is larger than the time to wake, a deadline was missed.
if(timeToWake < xLastWakeTime and
currentTickCount > timeToWake) {
handleMissedDeadline();
}
}
// No tick count overflow. If the timeToWake has not overflown
// and the current tick count is larger than the time to wake,
// a deadline was missed.
else if(timeToWake > xLastWakeTime and currentTickCount > timeToWake) {
handleMissedDeadline();
}
}
void FixedTimeslotTask::handleMissedDeadline() {
#ifdef DEBUG
sif::warning << "FixedTimeslotTask: " << pcTaskGetName(NULL) <<
" missed deadline!\n" << std::flush;
#endif
if(deadlineMissedFunc != nullptr) {
this->deadlineMissedFunc();
}
}

85
osal/FreeRTOS/FixedTimeslotTask.h
View File

@ -1,26 +1,27 @@
#ifndef POLLINGTASK_H_
#define POLLINGTASK_H_
#ifndef FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_
#define FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_
#include <framework/devicehandlers/FixedSlotSequence.h>
#include <framework/tasks/FixedTimeslotTaskIF.h>
#include <framework/tasks/Typedef.h>
extern "C" {
#include "FreeRTOS.h"
#include "task.h"
}
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
class FixedTimeslotTask: public FixedTimeslotTaskIF {
public:
/**
* @brief The standard constructor of the class.
*
* @details This is the general constructor of the class. In addition to the TaskBase parameters,
* the following variables are passed:
*
* @param (*setDeadlineMissedFunc)() The function pointer to the deadline missed function that shall be assigned.
*
* @param getPst The object id of the completely initialized polling sequence.
* Keep in mind that you need to call before vTaskStartScheduler()!
* A lot of task parameters are set in "FreeRTOSConfig.h".
* @param name Name of the task, lenght limited by configMAX_TASK_NAME_LEN
* @param setPriority Number of priorities specified by
* configMAX_PRIORITIES. High taskPriority_ number means high priority.
* @param setStack Stack size in words (not bytes!).
* Lower limit specified by configMINIMAL_STACK_SIZE
* @param overallPeriod Period in seconds.
* @param setDeadlineMissedFunc Callback if a deadline was missed.
* @return Pointer to the newly created task.
*/
FixedTimeslotTask(const char *name, TaskPriority setPriority,
TaskStackSize setStack, TaskPeriod overallPeriod,
@ -28,16 +29,18 @@ public:
/**
* @brief The destructor of the class.
*
* @details The destructor frees all heap memory that was allocated on thread initialization for the PST and
* the device handlers. This is done by calling the PST's destructor.
* @details
* The destructor frees all heap memory that was allocated on thread
* initialization for the PST and the device handlers. This is done by
* calling the PST's destructor.
*/
virtual ~FixedTimeslotTask(void);
ReturnValue_t startTask(void);
/**
* This static function can be used as #deadlineMissedFunc.
* It counts missedDeadlines and prints the number of missed deadlines every 10th time.
* It counts missedDeadlines and prints the number of missed deadlines
* every 10th time.
*/
static void missedDeadlineCounter();
/**
@ -46,13 +49,14 @@ public:
static uint32_t deadlineMissedCount;
ReturnValue_t addSlot(object_id_t componentId, uint32_t slotTimeMs,
int8_t executionStep);
int8_t executionStep) override;
uint32_t getPeriodMs() const;
uint32_t getPeriodMs() const override;
ReturnValue_t checkSequence() const;
ReturnValue_t checkSequence() const override;
ReturnValue_t sleepFor(uint32_t ms) override;
ReturnValue_t sleepFor(uint32_t ms);
protected:
bool started;
TaskHandle_t handle;
@ -60,32 +64,35 @@ protected:
FixedSlotSequence pst;
/**
* @brief This attribute holds a function pointer that is executed when a deadline was missed.
*
* @details Another function may be announced to determine the actions to perform when a deadline was missed.
* Currently, only one function for missing any deadline is allowed.
* If not used, it shall be declared NULL.
* @brief This attribute holds a function pointer that is executed when
* a deadline was missed.
* @details
* Another function may be announced to determine the actions to perform
* when a deadline was missed. Currently, only one function for missing
* any deadline is allowed. If not used, it shall be declared NULL.
*/
void (*deadlineMissedFunc)(void);
/**
* @brief This is the entry point in a new polling thread.
*
* @details This method, that is the generalOSAL::checkAndRestartPeriod( this->periodId, interval ); entry point in the new thread, is here set to generate
* and link the Polling Sequence Table to the thread object and start taskFunctionality()
* on success. If operation of the task is ended for some reason,
* the destructor is called to free allocated memory.
* @brief This is the entry point for a new task.
* @details
* This method starts the task by calling taskFunctionality(), as soon as
* all requirements (task scheduler has started and startTask()
* has been called) are met.
*/
static void taskEntryPoint(void* argument);
/**
* @brief This function holds the main functionality of the thread.
*
*
* @details Holding the main functionality of the task, this method is most important.
* It links the functionalities provided by FixedSlotSequence with the OS's System Calls
* to keep the timing of the periods.
* @details
* Core function holding the main functionality of the task
* It links the functionalities provided by FixedSlotSequence with the
* OS's System Calls to keep the timing of the periods.
*/
void taskFunctionality(void);
void checkMissedDeadline(const TickType_t xLastWakeTime,
const TickType_t interval);
void handleMissedDeadline();
};
#endif /* POLLINGTASK_H_ */
#endif /* FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_ */